In particular in the field of servo-drive technology, transmissions with a very small amount of backlash and high rigidity under very high dynamic loading are demanded. In addition, a plurality of transmission possibilities is demanded in this field, and this results in a large number of different transmissions. This is the reason for the fact that these transmissions are not kept in store in most cases, but are made to order. Especially in the case of unusual transmission ratios, this may result in substantial waiting periods which entail various disadvantages. Due to the large number of different transmission possibilities, it has, up to now, been impossible to provide all the variants of one series of transmission within the shortest possible time.
It is therefore the object of the present invention to provide a transmission unit which permits a more flexible structural design with regard to various transmission possibilities.